| Subject | [PATCH 22 of 66] clear page compound | Date | Wed, 03 Nov 2010 16:27:57 +0100 | From | Andrea Arcangeli <> |
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From: Andrea Arcangeli <aarcange@redhat.com>
split_huge_page must transform a compound page to a regular page and needs ClearPageCompound.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> ---
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -347,7 +347,7 @@ static inline void set_page_writeback(st * tests can be used in performance sensitive paths. PageCompound is * generally not used in hot code paths. */ -__PAGEFLAG(Head, head) +__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head) __PAGEFLAG(Tail, tail) static inline int PageCompound(struct page *page) @@ -355,6 +355,13 @@ static inline int PageCompound(struct pa return page->flags & ((1L << PG_head) | (1L << PG_tail)); } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline void ClearPageCompound(struct page *page) +{ + BUG_ON(!PageHead(page)); + ClearPageHead(page); +} +#endif #else /* * Reduce page flag use as much as possible by overlapping @@ -392,6 +399,14 @@ static inline void __ClearPageTail(struc page->flags &= ~PG_head_tail_mask; } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline void ClearPageCompound(struct page *page) +{ + BUG_ON((page->flags & PG_head_tail_mask) != (1 << PG_compound)); + clear_bit(PG_compound, &page->flags); +} +#endif + #endif /* !PAGEFLAGS_EXTENDED */ #ifdef CONFIG_MMU
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